1. Technical Field of the Invention
The present invention relates to the technical field of an image processing method and an image processing apparatus which perform a correction of image quality deterioration such as chromatic aberration of magnification, distortion aberration, deterioration of marginal luminosity, defocusing or the like derived from a taking lens that occurs in an image recorded with a film with lens, a low-priced compact camera, a digital camera or the like in a digital photoprinter or the like which obtains image data either by photoelectrically reading an image optically recorded with a taking lens of a silver halide type photographic camera or the like or direct from an image recorded with the digital camera or the like and then subjects the thus obtained image data to predetermined processing to obtain a print (photographed) reproducing the recorded image as an output image.
2. Prior Art
Heretofore, the images recorded on photographic films such as negative films and reversal films (which are hereunder referred to simply as xe2x80x9cfilmsxe2x80x9d) have been commonly printed on light-sensitive materials (photographic paper) by means of a real exposure, namely, direct (analog) exposure in which the light-sensitive materials are exposed by projecting the image on the film.
A new technology has recently been introduced and this is a printer that relies upon digital exposure. Briefly, the image recorded on a film is read photoelectrically, converted to digital signals and subjected to various image processing operations to produce image data for recording purposes; recording light that has been modulated in accordance with the image data is used to scan and expose a light-sensitive material to record an image (latent image), which is subsequently developed to produce a print (photograph). The printer operating on its principle has been commercialized as a digital photoprinter.
In the digital photoprinter, images are handled as digital image data so that an image processing condition at the time of printing can be established by image data processing. Therefore, correction of washed-out highlights or dull shadows caused by photographing with backlight, an electronic flash or the like, sharpness processing (sometimes referred to simply as xe2x80x9csharpeningxe2x80x9d) or the like are favorably performed to produce a high quality print which has never been realized by a conventional direct exposure.
However, a case may occur that even if image data processing is performed on the image data of the image taken or recorded on the film, quality of the output image on the print can not adequately be improved. The case, for example, illustrates chromatic aberration of magnification, distortion aberration, deterioration of marginal luminosity, defocusing or the like derived from performance (aberration characteristic) of a lens mounted on the camera used to take the image.
A color image is formed of three primary colors: red (R), green (G) and blue (B). Since refractive index of the lens (imaging magnification) varies subtly with wavelength, the imaging magnifications of R, G and B lights are different from each other to generate the chromatic aberration of magnification. As a result, the image reproduced from the film has a definite color divergence.
In order to obtain a satisfactory and appropriately recorded image, a plane that is perpendicular to an optical axis must be focused on an imaging plane in correspondence with the plane. In fact, however, an ordinary lens has the imaging positions displaced along the optical axis and the resulting displacements of the focused positions in the axial direction cause the distortion, namely, distortion aberration of the focused image. As a natural consequence, the reproduction of the image taken on the film is distorted.
Moreover, in the image focused through the taking lens, by originating in a lens (aberration) characteristic that luminosity is deteriorated from the center area toward marginal areas of the image in accordance with so-called law of cosine to the fourth power (cos4), luminosity at the marginal areas or edges of the image becomes insufficient or dark, namely, so-called deterioration of marginal luminosity occurs.
Also, owing the aberration characteristic of the taking lens, a focal divergence increases in the marginal areas of the image to generate defocusing (Point Spread Function: PSF) therein.
In such way, owing the aberration characteristic of the taking lens, image quality deterioration such as color divergence, distortion in shape, deterioration of marginal luminosity, defocusing or the like occurs in the output image.
If a camera such as a single-lens reflex camera or the like that needs a cost to some extent is used, high-precision lens elements may be used and a plurality of lens elements combined to correct various aberrations including chromatic aberration of magnification, distortion aberration, deterioration of marginal luminosity, defocusing and the like may be used whereupon an appropriate image can be recorded on the film. However, cameras such as films with lens and compact cameras required to be a low cost can not use high-cost lenses so that the image quality deterioration such as chromatic aberration of magnification, distortion aberration, deterioration of marginal luminosity, defocusing or the like will develop in the images recorded on films. As a result, the image reproduced on the print will eventually be of low quality.
To deal with this problem of image quality deterioration which can not enhance the image quality of output image on the print, techniques have been proposed in connection with an image processing method and apparatus and typical examples of such technologies are disclosed in Unexamined Published Japanese Patent Applications (kokai) No. 287360/1995 and No. 281613/1997. The latter discloses the technique related with an image processing method and apparatus which perform image corrections in accordance with the aberration characteristic of a lens obtained via a lens information acquisition device. It points out that the technique can correct the aberration derived from the lens, prevent the image quality deterioration at marginal areas of the image and obtain a high-quality image in a constant manner.
The former example, i.e., Unexamined Published Japanese Patent Application (kokai) No. 287360/1995, points out that processing information of a film with lens, for example, a lens type recognizing code (code number for recognizing the type of the taking lens) of the taking lens of the film with lens is recorded on the film or the like of the film with lens; then the thus recorded lens type recognizing code is automatically read by utilizing a reading device or the like; hence the deformation caused by the distortion which has been derived from the aberration characteristic of the taking lens can be corrected.
However, a case may occur that the lens type recognizing code of the taking lens can not be obtained because the lens information acquisition device made a reading error of the lens type recognizing code of the taking lens, or because the lens type recognizing code itself of the taking lens has not been recorded. In this case, the aforementioned ordinary technique is not capable of correcting image quality deterioration (hereinafter referred to simply as xe2x80x9cimage correctionxe2x80x9d) in some cases derived from the taking lens such as distortion aberration, chromatic aberration of magnification, deterioration of marginal luminosity, defocusing or the like so that it can not prevent the image quality deterioration. Moreover, there are some cases in which information related with the lens is obtained; correction intensity to perform the above-mentioned image correction is automatically selected based on the thus obtained information; and the correction of image quality deterioration is performed, when the film is a film with lens which is exposed in a curved form, the correction of aberration can not be appropriately performed only by correcting the aberration characteristic of the taking lens so that distortion aberration or chromatic aberration of magnification still remains uncorrected on the image after subjected to correction; hence, the image quality deterioration can not be prevented.
In a conventional way, the reproduced image after subjected to image correction can not be verified on a monitor so that an operator is not always capable of obtaining a satisfactory print and must print out the reproduced image after subjected to correction to judge whether the image is appropriate or not. Moreover, the operator conventionally establishes correction intensity such as correction direction, correction quantity and the like on each of the images recorded on the film judging from the film to perform the correction of image quality deterioration on an image basis so that the operator must print out the reproduced image after subjected to correction from image to image to judge whether the correction is appropriately performed or not. Hence, there is a problem of aggravation of efficiency due to a significant waste of time and print output.
Further, when the image correction is performed on all of the images recorded on the film, if information on the taking lens can not be obtained so that image correction can not be automatically performed based on the aberration characteristic of the lens, though the lens used in shooting being the same and therefore the lens aberration is the same, a correction condition must be manually set from frame to frame; hence, there is a problem that appropriate and uniform images can not be obtained in a rapid and effective way by the same image correction which does not depend on individual frames.
There is a case in which all images recorded on the film were not always taken with the same camera, namely, a lens having the same aberration characteristic; there is also another case in which images recorded on the same film have different image quality deterioration such as distortion aberration, chromatic aberration of magnification, deterioration of marginal luminosity, defocusing or the like from each other. In these cases, there is a problem that the same image correction can not be performed on all images recorded on one film.
In the case of the film, particularly, of an ordinary 135 size or a film with lens, the above-mentioned correction of image quality deterioration can not be performed by the above-mentioned technique which automatically performs correction by reading the recognizing code of the film with lens involving lens type, for example, the lens type so as to automatically recognize the lens type. Hence, there is a problem that the image quality deterioration can not be prevented.
In such case, for the purpose of correcting the image quality deterioration such as distortion aberration, chromatic aberration of magnification, deterioration of marginal luminosity, defocusing or the like, it may be possible that firstly an image correction method of each image, correction intensity or the like based on its correction image correction method is manually designated, secondly whether the correction is appropriate or not is judged as looking at the corrected image displayed on a monitor and lastly an appropriate correction is established. However, an establishing operation of the appropriate correction of each image as looking at the monitor on an image basis is troublesome for the operator and aggravates work efficiency when a voluminous printout is performed. Moreover, a case may occur that correction of aberration derived from the taking lens is overlooked; hence, there is a problem that a high-quality image can not always be obtained.
It is, therefore, a first object of the present invention to solve the above problems in the known arts and to provide an image processing method and apparatus that are capable of performing correction of image quality deterioration, namely, correction of distortion aberration, correction of chromatic aberration of magnification, correction of marginal luminosity, correction of defocusing or the like in an appropriate way to prevent the image quality deterioration, even when the image quality deterioration is not appropriately corrected using the obtained lens type recognizing code of a taking lens or even when the lens type recognizing code can not be obtained and moreover that is capable of performing correction of the above-described image quality deterioration in an efficient, appropriate and uniform manner to prevent the image quality deterioration, even when the image correction is performed on a plural of mages recorded on the same film or the like.
A second object of the present invention is to solve the above problems in the known arts and to provide an image processing method and apparatus that are capable of performing a consistent and appropriate correction of aberration, namely, the image deterioration correction of distortion aberration, chromatic aberration of magnification, deterioration of marginal luminosity or defocusing in a uniform and appropriate way without being influenced with an operator""s experience, even when reading error of the lens type recognizing code of the taking lens occurs or even when the lens type recognizing code has not been recorded on the film and moreover that are capable of effectively obtaining a satisfactory finishing without forgetting the correction of aberrations derived from the taking lens.
In order to achieve the first object, a first aspect of the present invention is to provide an image processing method comprising the steps of obtaining an input image data from an image recorded optically with a taking lens, displaying a reproduced image of the image based on the thus obtained input image data on a monitor or outputting it as a hardcopy, designating whether correction of image quality deterioration is performed or not based on the reproduced image either displayed on the monitor or reproduced as the hardcopy, performing, when the correction of the image quality deterioration is performed in accordance with the designation of this performance, at least once a sequential process of the image quality deterioration including the steps of designating a correction intensity of the image quality deterioration in accordance with the reproduced image either displayed on the monitor or reproduced as the hardcopy, performing the correction of the image quality deterioration with the correction intensity on the input image date, as well as displaying the corrected reproduced image after the correction of the image quality deterioration is performed on the monitor or outputting it as the hardcopy, thereby establishing appropriately the correction intensity, and performing the correction of the image quality deterioration on the input image data based on the thus established correction intensity to obtain output image data.
Preferably, the image quality deterioration is at least one of chromatic aberration of magnification, distortion aberration, deterioration of marginal luminosity and defocusing derived from the taking lens.
Preferably, a correction step of correction intensities capable of performing designation at the time of designating the correction intensity differs between the chromatic aberration of magnification and distortion aberration.
Preferably, the correction intensity is at least one of correction direction and correction quantity of the image quality deterioration.
Preferably, the sequential process of the image quality deterioration are repeated until a corrected state of the corrected reproduced image either displayed on the monitor or reproduced as the hardcopy comes to be appropriate.
Preferably, the correction of the image quality deterioration is set either based on a correction function, correction coefficients which are used in the correction function and which change in accordance with the correction intensity and a position information of the input image data or based on the correction function which changes in accordance with the correction intensity and the position information of the input image data.
Preferably, when the reproduced image or the corrected reproduced image is displayed on the monitor or outputted as the hardcopy, one of a grid and a straight line as a reference of the correction intensity is provided in the reproduced image or the corrected reproduced image.
Preferably, the correction of the image quality deterioration is performed on the image in a first direction of the recorded image and in a second direction of the recorded image which is perpendicular to the first direction separately or simultaneously.
Preferably, when the taking lens is a lens of a film with lens, the correction of the image quality deterioration is performed on the image in each of a first direction of the recorded image and a second direction of the recorded image which is perpendicular to the first direction separately.
Preferably, the image on which the correction of the image quality deterioration derived from the taking lens has been performed is one image among a plurality of images optically taken with the taking lens and wherein, when each input image data of these plurality of images is obtained and the correction of the image quality deterioration derived from the taking lens is performed on the thus obtained input image data, the correction of the image quality deterioration is performed on each of the input image data of remaining images of the plurality of images using the correction intensity established on the one image on which the correction of the image quality deterioration has been performed to obtain each output image data.
Preferably, the correction of the image quality deterioration is continuously performed on the plurality of images.
Preferably, the plurality of images are contained in a same case or a same piece.
Preferably, the plurality of images are contained in a different case or a different piece.
Preferably, the one image on which the correction intensity has been established is a leading image of the plurality of images and wherein correction of the image quality deterioration is performed on all of the remaining images of the plurality of images using the correction intensity thus established.
Preferably, the correction intensity established on the one image is stored, then read when the correction of the image quality deterioration is performed on the remaining images of the plurality of images and used for performing the correction of the image quality deterioration.
It is preferable that the plurality of images are all of images recorded on a film, wherein the correction intensity to be used for all of images recorded on the film has previously been established on one image among images recorded on the film and wherein the correction of the image quality deterioration is performed on all of images recorded on the film using the established correction intensity.
Preferably, the plurality of images have been recorded on a film with a same camera without the film being rewound and taken out and wherein the plurality of images are subjected to the correction of the image quality deterioration to produce the output image data.
Preferably, the images recorded with the same camera without the film being rewound and taken out are judged by information recorded in a photographed film or on a film cartridge.
Preferably, the information recorded in the photographed film is cartridge mid-roll change information which is additionally recorded in a frame of a film at a time of shooting with a camera having a function capable of changing the film cartridge in a mid-roll state and wherein images of a plurality of frames within a range of images of frames in the film which have been judged as being shot with the same camera without changing the film cartridge in the mid-roll state by the cartridge mid-roll change information are all subjected to the correction of the image quality deterioration with the correction intensity established on the image of a first designated frame.
Preferably, even if the cartridge mid-roll change information has judged that the film cartridges were changed in the mid-roll state, when images of the frames in the film have been shot with the same camera, the images of the frames are subjected to the correction of the image quality deterioration with the correction intensity established on the image of the first designated frame.
Preferably, after all of the corrections of the image quality deterioration to be performed on images recorded on the film are performed and all of the output image data are obtained, the correction intensity is cleared.
Preferably, the image processing method further comprises the steps of storing the input image data of the image optically recorded with the taking lens and the correction intensity in correspondence therebetween or storing the output image data itself after subjected to the correction of the image quality deterioration, keeping them stored for a predetermined period of time, and reading the input image data and the correction intensity or the output image data after subjected to the correction of the image quality deterioration in accordance with a customer""s order to produce an output image data for reprint.
A second aspect of the present invention is to provide an image processing apparatus for obtaining image data from an image optically recorded with a taking lens and performing correction of image quality deterioration derived from the taking lens on the thus obtained image data, comprising at least one of a monitor on which a reproduced image based on the image data obtained from the image is displayed and a printer which outputs the reproduced image as a hardcopy image, a correction designating device which performs designation as to whether the correction of the image quality deterioration derived from the taking lens is performed or not based on the reproduced image of the image either displayed on the monitor or outputted as the hardcopy image, a temporary correcting device which, when the correction of the image quality deterioration is performed according to this designation, designates a correction intensity of the image quality deterioration in accordance with the reproduced image either displayed on the monitor or outputted as the hardcopy image, performs the correction of the image quality deterioration as well as displays a corrected reproduced image after subjected to the correction on the monitor or outputs it as the hardcopy image each time the correction of the image quality deterioration is performed, a correction intensity establishing device for establishing the correction intensity from the corrected reproduced image after subjected to the correction of the image quality deterioration which has been either displayed on the monitor or outputted as the hardcopy image by the temporary correcting device, and a correcting device for performing the correction of the image quality deterioration on the image based on the correction intensity thus established to obtain an output image data.
Preferably, the image quality deterioration is at least one of chromatic aberration of magnification, distortion aberration, deterioration of marginal luminosity and defocusing derived from the taking lens.
Preferably, the correction intensity is at least one of correction direction and correction quantity of the image quality deterioration.
Preferably, the image processing apparatus further comprises a continuous correcting device as an additional device which, for the purpose of continuously performing the correction of the image quality deterioration on a plurality of images optically recorded with the taking lens, continuously performs the correction of the image quality deterioration using the correction intensity of one image among the plurality of images established by the correction intensity establishing device to all of the individual image data of the plurality of images to obtain the output image data.
In order to achieve the second object, a third aspect of the present invention is to provide an image processing method for obtaining image data from an image optically recorded with a taking lens to perform image correction of at least one of corrections of chromatic aberration of magnification, distortion aberration, deterioration of marginal luminosity and defocusing on the image data, comprising the steps of designating a lens type of the taking lens manually, and performing the image correction on the image data using the thus designated lens type and a position information of the image.
A fourth aspect of the present invention is to provide an image processing apparatus for obtaining image data from an image optically recorded with a taking lens to perform image correction of at least one of corrections of chromatic aberration of magnification, distortion aberration, deterioration of marginal luminosity and defocusing on the image data, comprising a lens type designating device for designating a lens type of the taking lens manually, and a correcting device for performing the image correction on the image data using the lens type designated by the lens type designating device and a position information of the image.
Preferably, when the image is recorded on the film with lens, the lens type designating device recognizes a recognizing code of the film with lens recorded on the film with lens to demand designation of the lens type automatically.
Preferably, when the image is an image recorded on a film with lens of an Advanced Photo System, the lens type designating device recognizes SSU INDICATOR as the recognizing code of the film with lens.